Brominated beta-naphthylindigo.



- UNITED. sA-

PATENT emc E ALBRECHT SCHMIDT AND ROBERT VO'SS, OF HfiCHST-ON-THE-MAIN, GERMAN Y, 'ASSIGNORS TO FARBWERKE, VORM. MEISTER LUCIUS 8: BRUNING, OF Hi'jCiHST-ON-THE-MAIN,GERMANY, I

A CORPORATION OF GERMANY.

BROMINATED BETA-NAPHTHYLINDIGOL No Drawing.

To all whom it may concern:

Be it known that we, ALBRECHT SCHMIDT,

- beta naphthylindigo does not allow of direct bromination, but rather that a complete destruction of the molecule of the naphthylin- WVe, however, have found digo takes place.

' that these references are not right in so far as bromo-substitution products of naphthylindigo may be obtained by a careful bromination. Even compared with beta-na h- .thylindigo, these products are distinguis ed shades.

This process may be carried out, for in stance, as follows:

Example I: 15 parts by eight of betanaphthylindigo are suspended in 500 parts by weight of carbon-tetra-chlorid, 13 parts by weight of bromin are added and all is stirred cold for 24 hours. After this it is filtered, washed subsequently with carbontetra-chlorid, and after drying, boiled with 10 parts by Weight of a bisulfite solution and 100 parts by weight of water, refiltered, washed again, and reboiled with alcohol, un til the filtrate runs oifwith a pure green color. The product is a dark green powder, containing approximately the amount of bromin calculated for mono-bromobetana hthylindigo. Itis solublein concentrated su furic acid with a blue color, a little redder than beta-naphthylindigo, very diflicultly soluble in most dissolving agents, more easily soluble in anilin, nitrobenzene and chloroform. In an alkaline hydrosulfite vat, cotton is dyed light green. with much faster tints, than those obtained with beta-naphthylindigo.

by their superior fastnessand clearness of Specification of Letters Patent; P t t d A Application filed March 24, 1908. Serial No. 422,91a'i Exam le II: 1.5 parts byweight of betanaphthylindigo are'sus'pended in 500 parts by Weight of carbon-tetra-chlorid, 53 arts by weight'of bromin are added and boi ed in a reflux cooling apparatus for 36 hours. The Working is carried out as in Example I. A blackish-green powder, is obtained containingon the average the ap roximate amount 'of bromin calculated or dibromo-beta naphthylindigo. This dyestuff dissolves in concentrated sulfuric acid with a reddish blue tint, it is very diflicultly soluble in the usual solvents, moderately soluble in nitrobenzene and anilin. In a vat it dyes cotton in light and fast green shades.

Example III: 15 parts by weight of naphthylindigo are entered in small. portions, being cooled by ice, into about 100 parts by weight of liquid bromin, and the mass stirred worked out as in Example I. The dyestuff forms a blackish green p.owder, containing the ap roximate quantity of bromin, calculated fbr tetra-bromo-beta-naphthylindigo,

sulfuric acid;.either by warming or in mono hydrate a blue violet solution is obtained.

the usualdiss'olving agents, somewhatmore easily soluble in nitrobenzene and anilin.

In the alkaline hydrosulfitevat cotton is dyed in clear and fast green tints.

for about 2 days while being-well cooled. It is then diluted with carbon tetra-chlorid is hardly at all-soluble in cold concentrated- The product is soluble only with difficulty in Havin now described our invention, what we claim is:

thylindigo, therein consisting that betanaphtially as described;

2. As new products, the brominated-beta naphthylindigoes dyeing cotton in the vat very fast clear green shades, being insoluble in the usual dissolving agents, soluble in conor nitrobenzene.

3. As a new roduct, the dibrominated Ibeta na hthy'lin igo being a dark green powcentrated sulfuric acid, monohydrate, anilin\ 1. The process herein described of making j brorno-substitutionsproducts' of beta-naphthylindigois treated with bromin, sub'starider soluble in concentrated sulfuric acid with as our invention, we have signed our names a refidish bllug colrln', very dlfliclltbi solublle in presence of two subscribing witnesses.

1n t e usua isso ving agents, airy easi y dissolved in nitrobenzene and anilin, forming 5 when treated with alkaline reducing agents like hydrosulfite a vet solution from which Witnesses: I Q cotton is dyed very fast clear green shades: JEAN GRUND, In testimony, that we claim the foregoing J CARL GRUND. 

